Carburetor



Aug.Y 7, 1934. 4 J. s. GULF 1,969,638

ATTORNEY/S M@ www HJM J. S. CULP CARBURETOR Aug. 7, 1934.

Filed July 13, 1931 3 Sheets-Sheet 2 INVENTOR. f5', Ca Z/Q.

Y '3J/A41 ATTORNEY/s Aug. '7, 1934.

J. s. cuLP CARBURETOR Filed July l5, 1951 3 Sheets-Sheet 5 M@ Ms* um Patented ug'. 7, 1934 UNITED STATI-:s

PATENT orgies CARBURETOR Jay S. Culp, Detroit, Mich., assignor to William F. Connolly, Detroit, Mich.

Application July 13, 1931, ySerial No. 550,553

9 Claims.

10v of mechanism and to secure various other ad- A housing O in connection with the casing C forms vantages as hereinafter set forth.

In the drawings:

Figure 1 is a vertical central section through*l my improved carburetor; n

' Figure 2 is a cross section in the plane transverse to that of Figure 1 and showing a different position of adjustment;

Figures 3 and 4 are horizontal sections respectively on lines 3-'3 and `4 1-4: of Figure 1. As shown, A is the engine inlet manifold which is provided with an upwardly extending inlet portion B to which the carburetor casing is attached. This carburetor casing includes a central member C which is secured to the portion B by Ysuitable means such as the screws D. The passage through the member C is contracted inits upper portieri to be'of substantially Venturi form and in the lower portion there is secured a spider member E which supports a centrally` arranged Slidingly mounted on and guided by the member F is a valve member G which is both manually and automatically operated as hereinafter described. The valve G has a centrally depending stem H which slidably` engages the hollowpost F. The stem H is hollowr and internally threaded to receive the threaded upper end I of a stem member J forming a downward extension of the stem I-I. At the lower end of the stem J is a collar K which has a lost motion connection with the stem by means of a cross pin L engaging a slightly enlarged aperture L in the stem. 'The' collar H is also provided with a shoulder for engaging a spring M sleeved upon said collar and having its F. Thus the resilient pressure of thespring M tends to draw the stems J and I-I downward and to withdraw the valve G from engagement with the restricted portion of the air passage through the member C. There is, however, a second spring N which is within the hollow, valve G and engages an annular recess in the post member F. The spring N opposes the operation of the spring M but is of lighter tension so that when both are ""free to operate, the spring M will overcome the upwardly projecting hollow post member F.'

upper end abutting against a bearing onthe post,

spring N and will lower the stem and valve G until the tension of said springs is in balance. However, to the extent of the lost motion between the pin L and the enlarged aperture L the spring a N can operate independently of the spring M to raise the valve G.

Surrounding the casing member C is a bell shaped casing memberL provided with radial guide portions O which telescopically engage the outer cylindrical surface of the member C. The l a return bent air inlet to the manifold. The fuel is introduced through ano'zzle P which centrally depends Afrom the ,bell shaped housing O. This nozzle receives fuel from a conduit Q which in 'v70 turn receives it from .any suitable pump (not shown) operating only when the engine is moving. vThe discharge of fuel from the nozzle P is meteredby a tapered metering pin R which projects upward from Ythe valve G and'is Vprovided -75 with a headR inside the valve and held in position bythe stem I. i The arrangement is' such that the metering pin is permitted sufficient lateral movement to nd its seat in the nozzle, and in the normal position of parts when the engine is not fin operation the valve G will be held by the spring N so as to completely close the nozzle P by the metering pin R. The housing O is adjustably secured to the housing member C by a bolt S and a spring S' sleeved thereon so that by adjusting this bolt the housing O may be either raised or lowered.' This will permit of properly setting the same so as to close the nozzle P by the metering pin R. when the engine is not in operation. A

As has been stated, the tension of the spring M being greater than Vthe tension of the spring N, it will overcome the latter and lower the valve G and metering pin R. Normally such movement is prevented by a rod T preferably extending upward through a guide T formed in the manifold A and bearing against the lower end of the collar K. The rod T is `operated by a bell crank lever U which in turn is actuated by a rod V leading to the accelerator pedal (not shown) Operation When the engine is at rest the nozzle P will be closed by the metering pin R., thereby preventing the discharge of any fuel. As soon,- however, as the engine is cranked and suction Yis produced in the manifold A, this will draw down the valve G against the tension of the spring N to take up the lost motion b etween the pin L andenlarged recess L. The lamount of gi y " form, a fuel inlet nozzle discharging downwardly i in` said 'poi-tion, 'anfairvalv insaid'inlet 'open-V ing in a downward direction and normally en-A 'gaging thefrestricted' 'portion of the venturi, means 'for'holding saidfvalve in its'rais'ed posh tion to restrict' the passage `offz't'irY through lsaid l inlet,y manually operable"means controlling 'said `7in e'as C'nrinovings aidfv alvefandlmeans'jfor ad 40,

' a `fuel `nozzle""discharging downwardly in saidfy tent permitted bythe accelerator.L 30

metering pin R so as to open the nozzle for the discharge of fuel required for idling. If, however, the rod V is pushed by the accelerator pedal the bell crank lever U will be rocked, withdrawing its bearing from the lower end of the rod T and permitting the spring N to move downward the collar K, stein J, valve G and metering pin R. Thiswill proportionately increaseboth the volumeof air'whichc'an pass through the Venturi passage and also the amount of fuely discharged through the orifice in the nozzle P. The amount of movement under the actuation of the spring M is limited to a point where the diminished tension of said spring is counterbavlanlce'd by *the* increased tension of the spring 'N.`f :`Any further@ opening movement of the valve "is eiic'ted through manifold suction. Thus the valve` G performs the combined functions of a throttle valve and an automatic air valve, therebysimplifying the construction of the carburetorn as a whole.' Furthermore, lthe' construction is one,`

which permits rapid acceleration,for'the initial 'opening'o'f the valvev G` and the metering 'pin Rf. '251' is accomplished' by the'ex'cess tension vofwtheh springV MV over that of the spring N, while for higher engine speeds manifold vsuction"may' be" 'depended uponfor opening the valve to "the eX-A What'I claim asmy invention is: u

1*.A carburetor comprising an airinlet having a' downwardly'directed portionjof' Venturi said valve, andim'etering means controllingftheu dischargeof fuel from saidno'zzlecaried by'said valve and adaptedto increasethe discharge ori-j j ice of' said' nozzle in' proportion to the increased opening ofthe'valv. 2."A carburetorcomprising an air inlet having a downwardly directed portion' of Venturi form, j

portionv "ofil the inlet," an air valve normallyvv en-' 'gagingjthe restricted portion' of said venturi :to re'strictp'the'passage of fair therethrough, said "Valve being movable downwar'dly'toopensaid." f passa'gc',"manually c'ontr'olled'ineans for'raisingfv saidV valve, 'a metering pin carried bysaidyalve 1 and' cooperating withsaid nozzle to increasethe discharge orifice in proportion to thlopening of:

raising'said valva'nd 'metering' 'pin to completely'l close the 'orice in said'noz'zle, said means permit-1` j 'jupon initial suction on"sai`d V`valve and limiting "ward direction, a"spring' offy lighter tensirabutf means for the niovenient'of saidvalve which isi independent of themanually controlled' means;m

3. LA 'carburetcr comprising an'air inlet"havingA a' restricted""portin, afuelf'nozzle "discharging downwardly'I in said restrictedwportin, an airf valve engaging said restricted portion to restrictif the flow of air therethrough, resilient means for being adapted to completely close said nozzle in the highest position of the valve, and yieldable means independent of said manually controlled means permitting a limited movement of said valve to open said nozzle for idling upon initial air suction upon said valve.

y4. A carburetor comprising an air inlet conduit lhaving I a contracted portion, a fuel nozzle larrangedfaxially of saidiinlettodischarge in said 'contractedprtiom an vair'valve movable axially of Asaid inlet towards or from said contracted portion, a metering pin carried by said air valve coperating with said nozzle to Variably restrict thedischarge of fuel therefrom, means for normallyholding said valve in a position to restrict the 'air'passagetlirough said contracted portion 'o'theinlet and to completely closer said nozzle yby said metering pin, manually operable means for vremoving said holding means, thereby permitting 'moving said valve to enlarge the air passage, landuto correspondingly increase. thehdischarge orice': insaid nozzle, and yieldable lmeans independent of' Ysaid i'nanuallyA operable means permitting a slight'moveinent,of'saidvalv and metering pinbyfair Suction to supplyv tliecar-K bureted'mixture'for idling; Y

5L Arcarburetcr comprisinga downwardly directed'air inlet conduit having a contracted por- 'Ati`o`n,` a bell' shaped housing ysurrounding k,said Vair inlet 'conduit and forming in connection,` there-l with a return bent inletpassage, a fueldischarge nozzle depending" from said bellshaped ycasing and projecting into thezlcontract'ed portionof sind animee, a valve 'movable yaxially.tviunn said alienating/with said nogzpjz'le to 'variabiy restrict the, /discharge orifice thereof, V manually voperable justing'; saidl bellifs'li'ape hojusingupon `s`aid"air.1 15 inietl toy-ary thegpositiorinfsaid nozzle ihrem; tion'to' said"'rnetering'pin."

6 'fA" carburet'or` comprising av downwardly directed air'inl'et .having agcont'ract'e'd portion'near its pper end, a' bell shapedhosing',surrounding 120 said 'airf Linlet conduit v andr 'forming connection therewithfareturn bent'air'inlet passage, a lfuel n'ozzle depending 'from said bell shaped housing t dischargefuel downwardlyinto :the contracted portion of said air' inlet/a valve' movable axially'125 of 'said' air inlet toitzards orffrom'f saidcontiiacted portion; a metering pin carried by said Avalve yand cooperating' with said nozzle to variably. restrict thedischaeeonfrce thereof, eisten depending from said van/ga' bearing yvitiijwhich said', enemigo is' siidablyv engaged; a spring,V sleeved oni's'aid 'stem andabutting againstfsaidf bearing, acollar on'said steni having" `a limitedf lO'St H 1O`t'ion`Y connection t lengaging 'said spring 'wheretingj afgainstsaidbe'aring and saidfvalve' to" i'eldllftlvthe Iat'l t0Y the kE'bidielt ffthl m0- ti'on tween said `collarflanduv stern,| fa mernber engagi gsaid" "collarf 'to y"normally supportA saldi@ van/eg ing' a; positionjadjcent 'to .theeomraeited portion of id inlet; and f withfsai'd'` metering Lpin completer iosirg'tiie,discharge prime msaid tozzle,n,n.'imuallyy operable 'means f 0`1f Withdraw- Jmtertopermitsaidnist men ones-,45

"discharge of.'y fuel from said nozzle'to'proportionf" `the"saie"td the air:opening-saidnieteringmeansL n erable means to furnish the air and fuel for idling.

7. The combination with an engine manifold provided with an upwardly extending portion forming a downwardly directed air inlet, of a carburetor comprising a casing connected to said upwardly extending portion of the manifold and having a contracted Venturi portion, a bell shaped housing surrounding said casing and forming in connection therewith a return bent air inlet passage to said manifold, a fuel nozzle depending from said bell shaped housing to discharge into the contracted portion of said casing, an air valve movable axially in said casing towards or from the contracted portion thereof, a metering pin carried by said valve and cooperating with said nozzle to variably restrict the discharge orifice thereof, a stem for said valve, a bearing in said casing in which said stem is slidable, a rod eX- tending upward through said manifold to engage said stem and to hold the same in a position where said valve restricts the air passage through said casing and said metering pin closes said nozzle, manually operable means for lowering said rod to permit the opening of said valve and the enlargement of the discharge orice in said nozzle and resiliently yieldable means independent of said manually operable means permitting a slight movement of said valve under air suction to open said nozzle to supply fuel for idling.

8. A carburetor Acomprising an air inlet conduit having a contracted portion, a fuel nozzle arranged axially of said inlet to discharge into said contracted portion, an air valve movable axially of said inlet towards or from said contracted portion, a. metering pin carried by said air valve cooperating with said nozzle to variably restrict the discharge of fuel therefrom, opposed springs reacting upon said valve to move the same in opposite directions, said springs being out of balance when said valve is in the restricted portion of said conduit with a preponderance of pressure by the spring urging the valve away from said restricted portion and manually operable means for moving said valve towards said restricted portion adjustable to various positions to limit the opposite movement of said valve.

9. A carburetor comprising an air inlet conduit having a contracted portion, a fuel nozzle arranged to discharge into said contracted portion, an annular valve movable axially of said inlet towards or from said contracted portion, a metering pin carried by said air valve cooperating with said nozzlekto variably restrict the discharge of fuel therefrom, a guide bearing for said valve, springs abutting against said guide bearing reacting upon said valvev to urge the same in opposite directions, said springs being out of balance when said valve is 'in engagement with the restricted portion of said conduitwith a preponderance of pressure by the spring for urging it away from such position, and a manually adjustable stop for variably limiting the movement of said valve away from said contracted portion.

JAY S. CULP. 

